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Topic: Dual Alternator Setup (Read 2663 times) previous topic - next topic

Re: Dual Alternator Setup

Reply #50 –
The sense wire is connected and the alternator is working as expected.  Do what ever you want, Bob. 
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Dual Alternator Setup

Reply #51 –
So the Delco drawing and website is not what actually happens all the time at the battery?  It's only till charged?

Most non gel or non optimas could and should have 14 volts constantly at a battery I would think?

All optimas and mk gels are made to have a max of 13.8 volts to them continuously. Better slightly less like the 13.6 recommended.

My Cummins dealer owner/shop foreman wanted to put in the delco sense alternator and he said I would always have 14 volts to my batteries.

Not being contrary  just trying to make sure for my own possible personal choices how things work.

I would temporarily clip or add an additional wire from the sense to the batteries just to see if the volts go up to the 14 volts the drawing shows?

What does the delco show at its output terminal?  With and without its sense wires?

Could the delco be defective?

Seems like a lot of volts gone somewhere?

Did you set up your system to pull power from  the start batteries?

You would think the sense system if working would compensate for any loads?
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Dual Alternator Setup

Reply #52 –
If trying to run the A/Cs off the alternator, why would you still use a diode type isolator?  The reason those big heat sinks are on the isolator is because they consume power (they have a voltage drop which makes heat). This means your alternator is working harder to make power that isn't charging the batteries.
1998 U270 34'

Re: Dual Alternator Setup

Reply #53 –
Quote from: krush –
If trying to run the A/Cs off the alternator, why would you still use a diode type isolator?
I know it's a pain to read through a whole long-winded thread from the very first post, but if you had, you'd know:

A.  I don't have a diode isolator.  I have a Victron Argo FET 200-2 isolator - different beast.  Very small internal voltage loss.

https://www.victronenergy.com/upload/documents/Datasheet-Argo-Fet-Battery-Isolators-with-alternator-energize-input-EN.pdf

B.  If I DO attempt to run my front A/C off the inverter, I will connect my 200 amp Delco 28Si directly to the coach batteries, bypassing my isolator.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Surely, no age has been more fraught with insecurity than our own present time."

Re: Dual Alternator Setup

Reply #54 –
I checked my start battery voltage right after we started the coach this morning and it getting charged at 14.2 volts.  30 minutes later at a rest stop the start batteries were getting charged at 13.2 volts (at normal idle speed) monitoring start battery voltage over 4 1/2 hours at highway speeds showed 13.6 to 13.8 volts with the headlights on.  Works exactly as expected.

The Delco alternator has a a smart voltage regulator.  It is not constant voltage and constant amps output
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Dual Alternator Setup

Reply #55 –
The Delco regulator is temperature compensated. In the Delco literature the voltages and performance graphs shown are at cold startup temperature (say 70 degrees). At startup the Delco sense adjusted charge voltage is approx 14 volts as Roger mentioned. As the alternator warms up the voltage reduces to approx 13.2 to 13.8 volts depending on alternator temperature. The Delco in my Roadtrek does the same thing. At startup I see approx 14.2 volts, going down the road I see approx 13.6 volts on my battery monitor. In the winter at freezing temps I have seen up to 15 volts at startup and it reduces as the alternator warms up. Roger's alternator is working as it should.
Peter and Tammy Fleming
1991 U300 GV 40 - Sold, owned for 4 years
Downsized to Roadtrek Popular 210 class B

Re: Dual Alternator Setup

Reply #56 –
I think the apparent reduction in charging voltage that Peter and Roger are describing is actually due to a little known fact: as electricity "heats up" the volts expand in length and circumference.  Because the volts are "bigger" (or "longer" depending on how you look at it) fewer of them can flow down a wire at any given time.  We observe this reduced flow rate as a smaller number on our voltmeter.

Although fewer volts are reaching the end of the wire, because they are "bigger" they each contain more "energy", so it's all good.  :thumbsup:
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Surely, no age has been more fraught with insecurity than our own present time."